Magnetic numbers?

My wife tried making me magnetic numbers from some thin magnetic sheets she got at staples. They stayed on through tech, but thats about it. 

With the challenge decal package announced, and my livery settled, its time to make new ones for the challenge (is it budget exempt to put the challenge sticjers on magnets???) And fir life after the challenge.

Im seeing lots of different stuff via google, but not sure of what i need. 

I want realy strong bond. Think "wont come off in the brush style car wash" strong. 

What do i need to get?

Here is what I buy via Amazon. 

https://www.amazon.com/gp/product/B01GQ048EQ/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

It is exactly what I have used on my Challenge numbers in the past.  I last bought again in early 2018 and that was to add the decal to the side of my  Gov't Mule Truck.

That truck logo has been in place for more than 1.5 years now with no issues.  

For the drag portion of The Challenge, it is wise to add a thin strip of masking tape to the leading edge of the magnet.  You are doing this to seal the edge and not allow air to get under the magnet; creating lift for the margent to peel off.  

Also try to apply the magnet in a fashion that does not place the magnet over body lines that could cause air gaps.  On the Miata, the beltline is indented and creates a gap/space for air to get under.  For high speeds try to protect that gap with some masking tape.  

Sample pic of tape application:  

Couple things. 

1. Dick Blick. The heavy sign grade magnetic sheets. 

2. Keep them flat.

3. Keep them dry. Some car paint doesn't seem to react well to having water trapped by magnets for more than a day or so. 

4. Keep things clean. I've very very occasionally seen something that I think is corrosive brake dust getting stuck to the magnet edges and causing paint issues. 

I bought about 10 square feet of white faced vinyl magnet sheet from McMaster-Carr in one of the heavier weights.  It was cheap and I still have some left after making several sets for various cars.

Heavier / thicker means more grip (at M-C they are rated by pull-off force), but it also means less compliance.  It is very important to store them flat as Seth says.  I stick mine to the inside of the garage door in the off-season.

John Welsh said:

Sample pic of tape application:  

Ugh, please don't do this. It looks like crap and makes us far less likely to use the photos.

Tom Suddard said:

John Welsh said:

Sample pic of tape application:  

Ugh, please don't do this. It looks like crap and makes us far less likely to use the photos.

Maybe using clear tape instead?

Just don't let it sit, that stuff is hell to remove if it gets old.

I bought mine from Autocross Digits. They stay in the box in the trunk of the car to keep them flat. They stay on very well, though I do tape them at the time trial. Usually with clear tape. A little 3M adhesive remover cleans up the mess in short order. 

Small rare earth magnets along the leading edge for some extra holding force? I don't have experience with this, just making a suggestion.

Adam

I’ve had good luck with the rectangular car magnets that Vistaprint sells.  Pretty thin, but strong enough to stay on at 130+mph in my experience.  They have a web design app that’s halfway decent, or you can get fancy and do your design in photoshop and upload it like I did.

As others have said, keeping them clean and flat is important.  I stick them to my chest freezer when not in use.

Get them warm before sticking them to the car.  Cold/stiff numbers are hell trying to get them to stick.  At the end of a day in the sun mine are hard to pull off.

This is what my magnet guy uses.

I got my set from an eBay seller "izoomgraphics.com".  They've stayed on at 75-80 mph for 2 hours when I forgot to remove them before leaving an autocross.

chrispy said:

I got my set from an eBay seller "izoomgraphics.com".  They've stayed on at 75-80 mph for 2 hours when I forgot to remove them before leaving an autocross.

I should note that I slap my vistaprint ones on before i leave the house and remove when i get home.  Most events are an hour away, they stay on quite well.

I bought some magnetic numbers from Racedecals.com, after about 2 years they aren't as "sticky".  I noticed the last couple events when it's been in the 90's that the edges are starting to get ripples in them.  I had some other magnetic numbers made by a local sign shop that also does wraps on dirt track cars.  The material is slightly thicker and the magnet seems to be stronger than what racedecals.com uses.  $80ish vs $10. 

adam525i said:

Small rare earth magnets along the leading edge for some extra holding force? I don't have experience with this, just making a suggestion.

Adam

That's exactly what I do with mine. They grip tightly, and are very unobtrusive.

In reply to Tom Suddard :

Safety first.  I’m not sending magnets flying at 115, and I’m not risking my paint with stickers.  I’ll look for some clear masking type tape.

What if we tie the painter's tape into our theme? Like, put it around all 4 sides of the number panel, as well as some tasteful stripes all over the car?

Especially if we use the cool green "Frog Tape" to match our green car.

We never had any problems with numbers coming off in my race group - matter of choosing the right material, I guess.

I never got to try them on my cars - one of my race cars has aluminum hinged panels (where all the numbers go) and the other was a fiberglass car....

I use that same thick white-faced sheeting from McMaster-Carr as mentioned above.  Comes in rolls and is pretty cheap and I haven't had any come off at highway speeds.

They aren't very compliant in the winter, though.  If you need to apply them in the cold I can neither confirm nor deny that a hotel room iron is a great tool for putting some heat into the material so they get bendy.

Here's a closer look from the event today.

They've stayed on when I once forgot to remove them before the 100 mile drive home. They held on fine in speeds up to about 80, in gusty wind conditions and through bumpy construction zones.

I run trackdecals.com magnetics and they are pretty solid. Never had them come off at 80+mph. For our chump car we just slapped the GRM stuff on the car(looks like total E36 M3 due to someone who didnt know how to apply decals). I think before we go to the autocross we may remove them and apply another to a magnet to make it look better.

To those who bought the blank magnet rolls, what thickness did you chose and any issues with that certain thickness?